Salts on the timber?Neither. Salts
Scrape it back and treat? Thats my plan anyway as i have to bolt 150mm timber to the side of existingLooks like white mould ... seen it loads of times in the old tenement attics with the old timbers at high humidity areas, e.g. above a bathroom extractor that hasn't been vented outside as you mention. It's not rot as such but would reckon rot could take over long term.
Yeah, instead of in the timber.Salts on the timber?
Would you scrape off and treat for good measureYeah, instead of in the timber.
Ive got the cuprinol 5 star.Yup, use a face mask before tackling as it can be an irritant. Was given a tip to use distilled vinegar on moulds in bathrooms etc as it soaks in wood killing the spores, bleach doesn't soak in so the mould can return.
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